The need to reduce pollution based upon carbon fuel consumption in vehicles is accelerating the thrust toward electric vehicles for use by the general public. It has long been known that a key problem is the way to recharge batteries frequently. Although battery charging has been known for many decades, most battery charging effort has been directed to charging the batteries of carbon fueled vehicles and charging the batteries of industrial vehicles such as forklifts and robots. Charging batteries for carbon fueled vehicles is mainly as a result of or following the correction of a fault in the charging system or the battery. Charging industrial vehicle batteries is accomplished in generally controlled environments with batteries of basically only a single type, on known vehicles and involving trained personnel.
Battery charging for primary motive power by the public in general is a wholly different matter. First, such systems should be arranged to minimize potential for electric shock to persons in the vicinity. The system should be designed to be as immune as possible to damage from repetitive normal use or predictable abnormal treatment. The systems should permit vehicles to readily engage a charging station, in a uniform manner to permit the maximum number of vehicles to use a maximum number of available charging stations (at least those that are available to the public at large). While vehicles will typically be charged when unused and parked at their home bases, they also will require obtaining charges that must be paid for at public and private commercial and municipal charging stations. Vehicles may be connected for a charge by means of a wire cable, such as that shown for a carbon fueled vehicle in U.S. Pat. No. 3,270,267. A more likely approach, however, may be to permit entering a station for a charge without the need for the operator to connect a cable. In U.S. Pat. No. 3,529,229, a probe mounted under a vehicle is inserted into a funnel shaped receptacle which is allowed to slide on bearings so as to accommodate minor misalignment of the vehicle with respect to the receptacle. In U.S. Pat. No. 3,596,018, a receptacle on the vehicle is funnel shaped and protected by spring loaded doors which can be pushed out of the way by a probe mounted on the charging station. The probe is mounted on springs so as to allow it to move slightly in any direction to accommodate a slight misalignment between the car and the vehicle. However, it will accommodate only a vehicle having its receptacle mounted at a standard height from the ground. Said patent also includes a probe which is disconnected from power until it is pushed by contact with the vehicle so as to make contact with the power of the station. While this renders it relatively safe from electrical shock to passersby, it does not protect the probe itself, and particularly the contacts thereof, from damage. A metal contact for an industrial tractor to be charged is illustrated in U.S. Pat. No. 3,273,038. An inductive coupling for charging an industrial vehicle is shown in U.S. Pat. No. 4,496,896. Spring loaded rubber shrouds are shown in U.S. Pat. No. 3,603,860; the shrouded probes are adapted to mate with conductive slots in, essentially, the bumper of the industrial vehicle.
All the foregoing notions have little to do with the need for the general public to have reliable, easy to use, generally available battery charging capability.